faced several times with cases where people died alone in an apartment, or was lost for various reasons (on forays into the forest, kidnapped, fatally injured, and so on). you may already have this service, and you may want to run the startup type to assist in such cases.
example: person a daily service is confirmed by email, telegram, etc. if within the specified period, the confirmation doesn't come, start the alarm procedure is selected by the user. type within two hours of the user and the selected addresses are bombing emailами, SMS and calls. then run the final alarm - ambulance, police, emergency. the user can select the desired treatments, respectively, and the rates may be different, the system of fines, etc.
certainly in the West already have that.